The field of gene therapy has undergone tremendous evolution over the last five years. Many studies presented in previous gene therapy meetings were primarily descriptive. As the field has evolved recently the barriers to its successful development have been defined and many scientists have focused on studying the basic biology that underlies these limitations. Recent excitement in the field has been the development of in vivo approaches to gene therapy. Furthermore, the clinical applications are beginning to appear in the literature as the initial human pilot experiments have been completed and the results collated. It is the goal of this conference to set forth a framework of cell and molecular biology which we feel is crucial to forming a basis for realizing the potential for gene therapy in the field of medicine. We will also integrate a review of the initial clinical trials in gene therapy, their relative merits, problems and potential utility. The general structure of the meeting is focused around particular vectors for gene delivery and diseases to provide an opportunity to critically evaluate both pre-clinical and clinical models. The topics that will be covered include: stem cells, nonviral vectors, regulatable vectors, adenoviral, retroviral, and episomal vectors, the immune response, genetic diseases, atherosclerosis, skeletal muscle and CNS disorders, AIDS, and cancer. This meeting differs from that of many others in the area of gene therapy in that its conceptual framework is focused on basic biology.